WPF Controls Slide out-then-in effect

Please Refer Above Document Outline. here i am using Border as a container ,
Ex:

<telerik:RadTabItem Name="PassPreviewTab"

                                Padding="4 1"

                                DropDownContent="Find Record">

                <telerik:RadTabItem.Content>

                    <Border Name="PassPreviewBorder"

                            BorderBrush="White"

                            BorderThickness="1"

                            Margin="10"

                            VerticalAlignment="Stretch"

                            HorizontalAlignment="Stretch"

                            Background="#FFE0F1F8"

                            CornerRadius="10">

                        <Border.Effect>

                            <DropShadowEffect Direction="150" Opacity="0.21" Color="#FF0C0C0C"/>

                        </Border.Effect>

                        <Border.Child>

                            <Grid>

                               // To Do : Add any controls
                            </Grid>

                        </Border.Child>

                    </Border>

                </telerik:RadTabItem.Content>

            </telerik:RadTabItem>

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Code :

<UserControl.Resources>

        <Storyboard x:Key="SlideIn" >

            <ThicknessAnimation Duration="0:0:.75" Storyboard.TargetProperty="Margin" From="500,0,-500,0" To="0" DecelerationRatio=".9" />

        </Storyboard>

        <Storyboard x:Key="SlideOut">

            <ThicknessAnimation Duration="0:0:.5" Storyboard.TargetProperty="Margin" To="-500,0,500,0" AccelerationRatio=".9"/>

        </Storyboard>

    </UserControl.Resources>

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Code for Slide In Effect for the Border

Storyboard storyboard = Resources["SlideIn"] as Storyboard;

storyboard.Begin(PassPreviewBorder);